Deficit Irrigation Scheduling Deficit Irrigation Scheduling forfor

Quality Quality WinegrapesWinegrapes

►►Improving Fruit QualityImproving Fruit Quality

Terry Prichard,Terry Prichard,Water Management Specialist Water Management Specialist

Dept. LAWR, HydrologyDept. LAWR, HydrologyUC DavisUC Davis

Improving Fruit QualityImproving Fruit Quality

►►Crop Load ManagementCrop Load ManagementPruning/ThinningPruning/Thinning

►►Canopy ManagementCanopy ManagementTrellis/Leaf RemovalTrellis/Leaf Removal

►►Crop Selection (drop)Crop Selection (drop)►►Ripeness HarvestingRipeness Harvesting►►Water DeficitsWater Deficits

Timing and SeverityTiming and Severity

Deficit IrrigationDeficit Irrigation

Vegetative growthVegetative growth --

Improved colorImproved color ++

Improved characteristicsImproved characteristics ++

YieldYield -- / / 00

Water volume/costsWater volume/costs ++

Water UseWater Use

ClimateClimateEvapotranspiration Reference (Evapotranspiration Reference (EToETo))

Sun InterceptionSun InterceptionSize of Canopy (Size of Canopy (KcKc))

Time of season (canopy expansion)Time of season (canopy expansion)SpacingSpacingTrellisTrellis

CIMISCIMIS

California Irrigation Management Information California Irrigation Management Information SystemSystem

Evapotranspiration Reference (Evapotranspiration Reference (EToETo) Rainfall) Rainfall

www.cimis.water.ca.govwww.cimis.water.ca.gov

Relationship Between Percent Land Surface Shaded and Vineyard Kc

0

0.5

1

1.5

10 20 30 40 50 60 70 80

Percent Shaded Area at Midday

Kc

Y = 0.017X + 0.002

LE Williams

44 x 0.017 = 0.75 Kc

May 10 7:30

Quad

Vertical

Balance Vegetative/Reproductive StructureBalance Vegetative/Reproductive Structure

Vineyard DevelopmentVineyard Development

Soil/Climate ResourcesSoil/Climate Resources►►SelectionSelection

RootstockRootstockCloneCloneSpacingSpacingTrellis typeTrellis type

Irrigation Management Irrigation Management PhilosophyPhilosophy

ControlledControlled water deficitswater deficits

can improve fruit qualitycan improve fruit quality

with little effect on yieldwith little effect on yield

Moderate Water DeficitsModerate Water Deficits

►►Reduce vegetative growthReduce vegetative growth

Shoot lengthShoot length

No. of lateral shootsNo. of lateral shoots

Increase diffused light to fruitIncrease diffused light to fruit

Relative Rate vs. Leaf Water Potential

0

20

40

60

80

100

120

4 5 7 8 9 10 11 12 13 14 15

Midday Leaf Water Potential (-bars)

Per

cent

age

Net Photosynthesis

Expansive Growth

Quality GoalsQuality Goals

►►Titratable acidityTitratable acidity►►Tartaric/Malic ratioTartaric/Malic ratio►►pHpH►►PotassiumPotassium

►►PhenolicsPhenolics

►►TanninsTannins

Extractable

Extractable

Cabernet Sauvignon, 2000Cabernet Sauvignon, 2000

LocationLocation

TonsTonsperperacreacre

Yield:Yield:PrunPrun wtwt

SolubleSolublesolidssolids((ooBrix)Brix)

AnthocyaninsAnthocyanins(mg g(mg g--11 FW)FW)

ParlierParlier

LodiLodi

OakvilleOakville

~9~9

~8~8

~6~6

9.19.1

11.311.3

6.56.5

22.822.8

23.423.4

23.923.9

7.97.9

18.218.2

27.527.5

TitratableTitratableacidityacidity(g/L)(g/L)

5.45.4

8.18.1

6.76.7

pHpH

4.24.2

3.73.7

3.93.9

Cabernet Deficit IrrigationCabernet Deficit Irrigation

% of ETc Variable 50 75 100 % of 100% Treatment Berry Size 80 90 100

Lodi Merlot 1998Lodi Merlot 1998

23.520.9 22.2

19.522.2

24.6

29.2 28.225.9

27.6

0

5

10

15

20

25

30

Yield(lbs/vine)

Treatments

1 2 43 5 6 7 8 9 10

Shoot, Root, and Berry Growth Rate

0

0.5

1

1.5

2

2.5

3

0 20 40 60 80100 120 140 160 180 200 220

Days from budbreak

Sho

ot E

long

atio

n R

ate

(cm

/day

)

012345678

Berry

Gro

wth

Rat

e (g

/day

/100

ber

ries)

Flowering Veraison Harvest

ShootsBerries

Roots

Mullins, 1992

Shoot Growth, Merlot, Lodi, 1999

020406080

100120140

5/6

5/135/205/27 6/3

6/106/176/24 7/1 7/8

7/15

Leng

th (c

m) T1

T3

T7T8

T9

T10

Irrigation of Quality WinegrapesIrrigation of Quality Winegrapes

►►DetermineDetermine

WhenWhen

How muchHow much

►►Achieve a predictable responseAchieve a predictable response

Developing a StrategyDeveloping a Strategy

►►When to Begin IrrigationWhen to Begin Irrigation

►►How much to ApplyHow much to Apply

To Accomplish the Set GoalFruit quality/yield

When to Begin IrrigationWhen to Begin Irrigation

►►Shoot GrowthShoot Growth

►►Tip RatingTip Rating

►►Mid day Leaf Water PotentialMid day Leaf Water Potential

►►Soil Based Monitoring DecisionSoil Based Monitoring Decision

Soil Moisture MeasurementSoil Moisture Measurement

►►Quantitative (quantity)Quantitative (quantity)

►►Qualitative (status)Qualitative (status)

Quantitative Moisture Measurement Quantitative Moisture Measurement MethodsMethods

►► Gravimetric / Volumetric Soil SamplingGravimetric / Volumetric Soil Sampling

►► Neutron Moisture MeterNeutron Moisture Meter

►► Dielectric Moisture SensorsDielectric Moisture Sensors

Capacitance ProbesCapacitance Probes

Frequency Domain Frequency Domain ReflectometryReflectometry (FDR)(FDR)

Pressure Chamber

Diurnal Leaf Water PotentialDiurnal Leaf Water Potential

0

2

4

6

8

1 3 5 7 9 11 13 15 17 19 21 23 1 3 5 7 9 11 13 15 17 19 21 23

Time

- Bar

s

Leaf Water Potential, Lodi Merlot Leaf Water Potential, Lodi Merlot 6/11/996/11/99

-12

-10

-8

-6

-4

-2

01 3 6 8 10 12 14 16 18 20 23

Time of Day 12 = Noon

Bars

Pressure BombPressure Bomb

►►When to sample (solar noon +When to sample (solar noon +-- 1.5 hr.)1.5 hr.)

►►No. of vines/block (6 average vines)No. of vines/block (6 average vines)

►►No. of leaves (2/vine)No. of leaves (2/vine)

►►Leaf selection (young/fully expanded)Leaf selection (young/fully expanded)

►►Leaf bagging (before excising)Leaf bagging (before excising)

►►Rate of pressure increase (3 sec/bar)Rate of pressure increase (3 sec/bar)

►►Leaf care (breaking veins)Leaf care (breaking veins)

Deficit Threshold + RDIDeficit Threshold + RDI

►►Begin irrigation at a specific leaf water Begin irrigation at a specific leaf water potential “threshold”potential “threshold”

►►After threshold, irrigate at fraction of After threshold, irrigate at fraction of full water usefull water use

When to Begin IrrigationWhen to Begin Irrigation

Deficit threshold methodDeficit threshold method

leaf water potential threshold leaf water potential threshold

--10 to 10 to --14 bars 14 bars

Leaf Water PotentialLeaf Water Potential

Selecting a ThresholdSelecting a Threshold

Enough to Stop Vegetative Growth-12-13-14-15

Variety, Wine Goal, Region

How Much WaterHow Much Water

Deficit threshold methodDeficit threshold method

After threshold, a fraction of full After threshold, a fraction of full vine water usevine water use

Full vine water use x RDI %Full vine water use x RDI %

RdiRdi % % ------ 35 35 -- 60%60%

How Much Water to ApplyHow Much Water to Apply

►►Volume of water to apply Volume of water to apply

Gallons per vine per weekGallons per vine per week

►►Not restart vegetative growthNot restart vegetative growth

►►Continue Sugar accumulation (Photosynthesis)Continue Sugar accumulation (Photosynthesis)

►►Protect fruit (cover)Protect fruit (cover)

Midday Leaf Water PotentialMidday Leaf Water Potential2000 Cabernet, Hopland2000 Cabernet, Hopland

-15.00

-13.00

-11.00

-9.00

-7.00

-5.005/20 6/3 6/17 7/1 7/15 7/29 8/12 8/26 9/9 9/23 10/7 10/21

Bar

s

T1 100% T4 12/60 T5 12/35 T6/12/35-60

Begin irrigation T1

Begin irrigation T4, T5, T6 Switch T6 to 60%

Determining the Irrigation VolumeDetermining the Irrigation Volume

EToETo X X KcKc = = Full Potential Vine Water Use (Etc)Full Potential Vine Water Use (Etc)

ETcETc X RDI% = Net Water Volume NeededX RDI% = Net Water Volume Needed

Net Irrigation X Emission Uniformity = Net Irrigation X Emission Uniformity = Gross Irrigation VolumeGross Irrigation Volume

Madera 2002Madera 2002Eto and precipitation from 2002Assumes that Leaf Water Potential Threshold was reached June 16HARVEST DATE: Septmember 15

A = B = C =

A x B: Potential Water D = E = F = G= [(C x D) - E - F] H =

I = G/H: J = (I x J x 0.623)

Date ETOCrop

CoeficientPotential

Water Use Use Thru Harvest

RDI Coeficient

Soil Contrib.

Effective Rainfall Net Irrigation

Emmision Uniformity

Gross Irrigation

Vine Spacing

Gallons per Vine / Period

Period Inches/ Kc (in) (in) Krdi (in) (in) (in) (%) (in) (sq feet)Period

Jun 16 - 30Jul 1 - 15Jul 16 - 31Aug 1 - 15Aug 16 - 31Sept 1 - 15Sept 16 - 30Oct. 1 -15Oct. 16 - 31

TotalGallons per vine applied through harvest =

Stn Id Station Date Jul CIMIS ETo (in) Precip (in) BiweeklyEto Ppt

145 Madera 6/16/2002 167 0.32 0145 Madera 6/17/2002 168 0.32 0145 Madera 6/18/2002 169 0.32 0145 Madera 6/19/2002 170 0.29 0145 Madera 6/20/2002 171 0.29 0145 Madera 6/21/2002 172 0.25 0145 Madera 6/22/2002 173 0.25 0145 Madera 6/23/2002 174 0.29 0145 Madera 6/24/2002 175 0.28 0145 Madera 6/25/2002 176 0.3 0145 Madera 6/26/2002 177 0.29 0145 Madera 6/27/2002 178 0.29 0145 Madera 6/28/2002 179 0.28 0145 Madera 6/29/2002 180 0.29 0145 Madera 6/30/2002 181 0.29 0 4.35 0

A = B = C =

A x B: Potential Water

Period ETOCrop

CoeficientPotential

Water Use Use Thru Harvest

Inches/ Kc (in) (in)Period

Jun 16 - 30 4.35 0.75 3.26 3.26Jul 1 - 15 4.46 0.75 3.35 3.35Jul 16 - 31 4.28 0.75 3.21 3.21Aug 1 - 15 3.84 0.75 2.88 2.88Aug 16 - 31 3.71 0.75 2.78 2.78Sept 1 - 15 3.16 0.75 2.37 2.37Sept 16 - 30 2.62 0.75 1.97 --Oct. 1 -15 2.18 0.75 1.64 --Oct. 16 - 31 1.70 0.75 1.28 --

Total 30.30 22.73 17.85

C = A x B:

Potential Water D = E = F =

G = [(C x D) - E - F]

TimePotential

Water Use Use Thru Harvest

RDI Coeficient

Soil Contrib.

Effective Rainfall Net Irrigation

Period (in) (in) Krdi (in) (in) (in)

Jun 16 - 30 3.26 3.26 0.60 0.50 0.00 1.46Jul 1 - 15 3.35 3.35 0.60 0.50 0.00 1.51Jul 16 - 31 3.21 3.21 0.60 0.50 0.00 1.43Aug 1 - 15 2.88 2.88 0.60 0.50 0.00 1.23Aug 16 - 31 2.78 2.78 0.60 0.50 0.00 1.17Sept 1 - 15 2.37 2.37 0.60 0.50 0.00 0.92Sept 16 - 30 1.97 -- 1.00 0.00 0.00 1.97Oct. 1 -15 1.64 -- 1.00 0.00 0.00 1.64Oct. 16 - 31 1.28 -- 1.00 0.00 0.00 1.28

Total 22.73 17.85 3.00 12.59

Madera Station 145

G = (C x D) - E - F] H = I = G / H: J = (I x J x 0.623)

Time Net IrrigationEmmision Uniformity

Gross Irrigation

Vine Spacing

Gallons per Vine / Period

Period (in) (%) (in) (sq feet)

Jun 16 - 30 1.46 0.90 1.62 77.00 77.69Jul 1 - 15 1.51 0.90 1.67 77.00 80.32Jul 16 - 31 1.43 0.90 1.58 77.00 76.01Aug 1 - 15 1.23 0.90 1.36 77.00 65.45Aug 16 - 31 1.17 0.90 1.30 77.00 62.34Sept 1 - 15 0.92 0.90 1.02 77.00 49.14Sept 16 - 30 1.97 0.90 2.18 77.00 104.74Oct. 1 -15 1.64 0.90 1.82 77.00 87.15Oct. 16 - 31 1.28 0.90 1.42 77.00 67.96

Total 12.59 13.98 670.79

Gallons per vine applied through harvest = 333

Madera Station 145

Eto and precipitation from 2002Assumes that Leaf Water Potential Threshold was reached June 16HARVEST DATE: Septmember 15

A = B = C =

A x B: Potential Water D = E = F =

G = [(C x D) - E - F] H =

I = G/H: J = (I x J x 0.623)

Time ETOCrop

CoeficientPotential

Water Use Use Thru Harvest

RDI Coeficient

Soil Contrib.

Effective Rainfall Net Irrigation

Emmision Uniformity

Gross Irrigation

Vine Spacing

Gallons per Vine / Period

Period Inches/ Kc (in) (in) Krdi (in) (in) (in) (%) (in) (sq feet)Period

Mar 1 -15 1.70 0 0.00 0.00 1 0 0 0.00 0.90 0.00 77 0Mar 16 - 31 1.98 0.15 0.30 0.30 1 0 0.6 -0.30 0.90 -0.34 77 -16Apr 1 - 15 2.66 0.22 0.59 0.59 1 0.59 0 0.00 0.90 -0.01 77 0Apr 16 -30 2.59 0.3 0.78 0.78 1 0.78 0 0.00 0.90 0.00 77 0May 1 -15 3.63 0.42 1.52 1.52 0.8 1.31 0 -0.09 0.90 -0.10 77 -5May 16 - 31 4.06 0.55 2.23 2.23 0.6 0.87 0.23 0.24 0.90 0.27 77 13Jun 1 - 15 4.26 0.65 2.77 2.77 0.4 0.9 0 0.21 0.90 0.23 77 11Jun 16 - 30 4.35 0.75 3.26 3.26 0.6 0.5 0 1.46 0.90 1.62 77 78Jul 1 - 15 4.46 0.75 3.35 3.35 0.6 0.5 0 1.51 0.90 1.67 77 80Jul 16 - 31 4.28 0.75 3.21 3.21 0.6 0.5 0 1.43 0.90 1.58 77 76Aug 1 - 15 3.84 0.75 2.88 2.88 0.6 0.5 0 1.23 0.90 1.36 77 65Aug 16 - 31 3.71 0.75 2.78 2.78 0.6 0.5 0 1.17 0.90 1.30 77 62Sept 1 - 15 3.16 0.75 2.37 2.37 0.6 0.5 0 0.92 0.90 1.02 77 49Sept 16 - 30 2.62 0.75 1.97 -- 1 0 1.97 0.90 2.18 77 105Oct. 1 -15 2.18 0.75 1.64 -- 1 0 1.64 0.90 1.82 77 87Oct. 16 - 31 1.70 0.75 1.28 -- 1 0 1.28 0.90 1.42 77 68

Total 51.18 30.91 26.04 7.45 0.83 12.63 14.03 593

Gallons per vine applied through harvest = 333

Monitor Effects of StrategyMonitor Effects of Strategy

Leaf Water PotentialLeaf Water PotentialVegetative GrowthVegetative GrowthYieldYieldQualityQualityWinemaker CommentsWinemaker Comments

Vine Water Use

vs.

Soil Water Reservoir

Vine Water Use

vs.

Soil Water Reservoir

Irrigation

Terry Prichard, Irrigation and Water Management SpecialistBlaine Hanson, Irrigation and Drainage Specialist

Larry Schwankl, Irrigation SpecialistPaul Verdegaal, Viticulture Farm Advisor Rhonda Smith, Viticulture Farm Advisor

University of California Cooperative ExtensionDepartment of Land, Air and Water Resources

University of California Davis

Supported in part by: Lodi-Woodbridge Wine Commission

Irrigation of Quality WinegrapesUsing

Micro-Irrigation Techniques

Irrigation of Quality Irrigation of Quality WinegrapesWinegrapes Using Using MicroMicro--Irrigation Irrigation

TechniquesTechniques

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